Submitted to: Maize Genetics Cooperation Newsletter
Publication Type: Research Notes
Publication Acceptance Date: 1/31/2003
Publication Date: 7/18/2003
Citation: BLAKEY, C.A., GOLDMAN, S.L., DEWALD, C.L., FRUTIGER, K. TRIPSACUM SR5: SHATTER RESISTANCE STUDY POPULATION. MAIZE GENETICS COOPERATION NEWS LETTER. 2003. V. 77. p. 55-56. Interpretive Summary:
Technical Abstract: In a collaborative arrangement with Stephen Goldman (PSRC, University of Toledo), and Chet Dewald (USDA-ARS-SPRRS), the preliminary steps towards the development of a study in diploid Tripsacum dactyloides (2n=2x=36). The new population has been designated as the SR5 population. The population has been involved in a large-scale seed-shattering and forage quality studies currently being conducted by the USDA-ARS-SPRRS, Woodward, OK (Chester Dewald, personal communication). Large tissue samplings of parental and F1, and a set of 240 out of 1250 SR5 F2 individuals were harvested during the summers of 2000 and 2001 in preparation for the Sabbatical Leave of the PI beginning in the Spring of 2001. Samplings of tissue were collected from each F2 individual from the same field for two successive years to reduce possibility of sampling error. These F2 sampling provide both a back-up population tissue set for the Ball State University on-site map population and as a of set quantitative trait loci (QTL) materials scored for seed shattering studies and eventual molecular analysis. The tissue harvested from this subset of 240 individuals of the SR5 F2 has limitations as the actual mapping population. Additional tissue harvests were not possible with the commencing of seed shattering studies in summer 2002 which allowed for nursery contamination by shattered seed. The QTL study materials remain in storage while characterized markers are assembled using the Tripsacum SR5 F2 mapping nursery at Ball State University, Muncie, IN. As of August 2001, DNA had been isolated and a set of 72 parental/F1 screening blots for the eight enzymes EcoRI, EcoRV, BamHI, Bgl II, DraI, SacI, XbaI, and HindIII had been constructed. Initial screening results of 5 of seven UMC maize bin markers screened have revealed clearly mappable polymorphisms. These five markers include: umc31 (4-6 bands), umc38 (1 bright monomorphic band + 3-7 polymorphic bands), umc44 (4-6 bands), umc65 (4-8 bands), umc66 (4-8 bands). Tripsacum typically has a more complex band pattern than that seen in maize. Previous experience with Tripsacum mapping has shown that to focus on the use of inter-specific probes aides in the reduction of the total observed complexity in data analysis to establish an initial map framework. Addition of other markers, particularly Tripsacum genomic markers (TDA), and cDNAs, will be added as they become available through collaborative efforts. The advantage of these materials is that they have the same parentage as the F2 mapping population being established at Ball State University, Muncie, IN, and represent one of the first molecular QTL sample set in Tripsacum extensively scored/rated for analysis of seed shattering and forage quality.